2006 INFINITI QX56 ignition

BASIC SERVICE PROCEDUREEC-81
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Revision: November 2009 2006 QX56
Without CONSULT-II
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
BBIA0380E

EC-82Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
FUEL PRESSURE CHECK
CAUTION:

Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.

Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the
quick connector o-ring maintains sealability.

Use Fuel Pressure Gauge Kit J-44321 and Fuel Pressure Adapter J-44321-6 to check fuel pressure.

Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C,
etc.). Fuel pressure gauge may indicate false readings due to varying engine loads and changes in
manifold vacuum.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because JA60 models do not have fuel return system.
1. Release fuel pressure to zero. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-17, "
INTAKE MANIFOLD" .

Do not twist or kink fuel hose because it is plastic hose.

Do not remove fuel hose from quick connector.

Keep fuel hose connections clean.
4. Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure Gauge (from kit J-44321) as shown in figure.

Do not distort or bend fuel rail tube when installing fuel pres-
sure gauge adapter.

When reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
5. Turn ignition switch ON (reactivate fuel pump), and check for fuel leakage.
6. Start engine and check for fuel leakage.
7. Read the indication of fuel pressure gauge.

During fuel pressure check, check for fuel leakage from fuel
connection every 3 minutes.
8. If result is unsatisfactory, go to next step.
9. Check the following.

Fuel hoses and fuel tubes for clogging

Fuel filter for clogging

Fuel pump

Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.
10. Before disconnecting Fuel Pressure Gauge and Fuel Pressure Adapter J-44321-6, release fuel pressure to zero. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
At idling:
Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
BBIA0390E

TROUBLE DIAGNOSISEC-83
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Revision: November 2009 2006 QX56
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionUBS00L02
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-84, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-88, "
Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G

TROUBLE DIAGNOSISEC-91
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Revision: November 2009 2006 QX56
Fail-safe ChartUBS00L04
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected itemsEngine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START 40
°C (104 °F)
More than approx. 4 minutes after
ignition ON or START 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric throttle control actuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode
Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-92Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
Symptom Matrix ChartUBS00L05
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOMRefer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-604
Fuel pressure regulator system 334444444 4 EC-82
Injector circuit11232 22 2EC-598
Evaporative emission system 334444444 4 EC-32
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-45
Incorrect idle speed adjustment 1 1 1 1 1EC-71
Electric throttle control actuator 112332222 2 2 EC-528
,
EC-534
,
EC-540
,
EC-545
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-71
Ignition circuit 11222 22 2EC-618
Main power supply and ground circuit 22333 33 23 EC-145
Mass air flow sensor circuit
1
12 2
222 2 EC-171,
EC-180
Engine coolant temperature sensor circuit
333
EC-192,
EC-205
Air fuel ratio (A/F) sensor 1 circuit EC-213
,
EC-223
,
EC-232
,
EC-241
,
EC-575

Throttle position sensor circuit 22EC-198
,
EC-320
,
EC-483
,
EC-485
,
EC-560
Accelerator pedal position sensor circuit 3 2 1EC-453
,
EC-547
,
EC-553
,
EC-567
Knock sensor circuit 23EC-335
Crankshaft position sensor (POS) circuit 2 2 EC-340
Camshaft position sensor (PHASE) circuit 3 2EC-347

EC-106Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
3LThrottle control motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open) [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
6GR Heated oxygen sensor 2
heater (bank 1) [Engine is running]

Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
12 R Power steering pressure sen-
sor [Engine is running]

Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned 0.4 - 0.8V
13 O Crankshaft position sensor
(POS) [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle Approximately 10V
[Engine is running]

Engine speed: 2,000 rpm Approximately 10V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E

EC-108Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2) [Engine is running]

Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
32 L EVAP control system pres-
sure sensor [Ignition switch: ON]
Approximately 1.8 - 4.8V
34 R/B Intake air temperature sensor [Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (bank 2) [Engine is running]

Idle speedApproximately 2.5V
40
41
42
63 Y/G
P
L
G Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 8 [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle BATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
45 L/Y EVAP canister purge volume
control solenoid valve [Engine is running]

Idle speed

Accelerator pedal: Not depressed even
slightly, after engine starting
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed: About 2,000 rpm (More than
100 seconds after starting engine) BATTERY VOLTAGE
(11 - 14V)
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
SEC984C
SEC985C
SEC990C
SEC991C

TROUBLE DIAGNOSISEC-109
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Revision: November 2009 2006 QX5647 YSensor power supply
(Throttle position sensor) [Ignition switch: ON]
Approximately 5V
48 SB Sensor power supply
(EVAP control system pres-
sure sensor) [Ignition switch: ON]
Approximately 5V
49 R/Y Sensor power supply
(Refrigerant pressure sensor) [Ignition switch: ON]
Approximately 5V
50 B Throttle position sensor 1 [Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed Less than 4.75V
51 W Mass air flow sensor [Engine is running]

Warm-up condition

Idle speed
1.0 - 1.3V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm 1.7 - 2.1V
55 R Heated oxygen sensor 2
(bank 1) [Engine is running]

Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - Approximately 1.0V
57 L/P A/F sensor 1 (bank 2) [Engine is running]

Warm-up condition

Idle speed Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
46
60
61
62 L/R
GR/R
O/W
Y/R Ignition signal No. 7
Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1 [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle 0 - 0.3V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm 0.1 - 0.6V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
SEC986C
SEC987C